1. Field of the Invention
The present invention relates to a swirling-flow burner with separate fuel and oxidizer supply, in particular, to a swirling-flow burner for use in gas-fuelled combustion reactors.
2. Description of the Prior Art
Burners of the swirling flow type are mainly used for firing gas-fuelled industrial furnaces and process heaters, which require a stable flame with high combustion intensities. Conventionally designed swirling-flow burners include a burner tube with a central tube for fuel supply surrounded by an oxidizer supply port. Intensive mixing of fuel and oxidizer in a combustion zone is achieved by passing the oxidizer through a swirler installed at the burner face on the central tube. The stream of oxidizer is, thereby, given a swirling-flow, which provides a high degree of internal and external recirculation of combustion products and thus a high combustion intensity.
As a general drawback of conventional swirling-flow burners of the above design, the burner face is at high gas flow velocities, as required for industrial burners of this design, exposed to overheating caused by the high degree of internal recirculation along the central axis of the combustion zone. Hot combustion products flow, thereby, back towards the burner face, which results in rapid heating up to high temperatures and, consequently, destruction of the face.